System for Electronic Adjustment of Effective Contrast Ratio in Photographic Reproduction.
DEPARTMENT OF THE AIR FORCE WASHINGTON D C
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The patent describes a system for controlling the contrast of light intensities falling upon a photosensitive surface after being transmitted through a transparency. Polarized light passes the transparency to a partially silvered mirror which reflects a portion of the light to an array of photosensors and also transmits a portion of the light to a ferroelectric plate. The photosensitive array and the ferroelectric plate are simultaneously scanned. At each scanning position of the photosensitive surface an electrical signal is caused to be applied to the corresponding scanned position of the ferroelectric plate, the intensity being controlled by a variable amplifier. The controlled light passing from the ferroelectric plate is transmitted through a polarizer to the photosensitive surface.
- Electrical and Electronic Equipment